XML 41 R2.htm IDEA: XBRL DOCUMENT v3.24.3
Shareholder Report
 12 Months Ended
Jul. 31, 2024
USD ($)
Holding
Holdings
Shareholder Report [Line Items]  
Document Type N-CSR
Amendment Flag false
Registrant Name Columbia Funds Series Trust I
Entity Central Index Key 0000773757
Entity Investment Company Type N-1A
Document Period End Date Jul. 31, 2024
Material Change Date Aug. 01, 2024
Columbia Tax-Exempt Fund (Class A)  
Shareholder Report [Line Items]  
Fund Name Columbia Tax-Exempt Fund
Class Name Class A
Trading Symbol COLTX
Annual or Semi-Annual Statement [Text Block] This annual shareholder report contains important information about Columbia Tax-Exempt Fund (the Fund) for the period of August 1, 2023 to July 31, 2024.
Shareholder Report Annual or Semi-Annual annual shareholder report
Additional Information [Text Block] You can find additional information about the Fund at
columbiathreadneedleus.com/resources/literature
. You can also request more information by contacting us at
1-800-345-6611.
Material Fund Change Notice [Text Block] This report describes changes to the Fund that occurred during the reporting period.
Additional Information Phone Number 1-800-345-6611
Additional Information Website columbiathreadneedleus.com/resources/literature
Expenses [Text Block]
What were the Fund costs for the reporting period?
(Based on a hypothetical $10,000 investment)
ClassCost of a $10,000 investmentCost paid as a percentage of a $10,000 investment
Class A
$
77		0.75
%
Expenses Paid, Amount $ 77
Expense Ratio, Percent 0.75%
Factors Affecting Performance [Text Block]
Management's Discussion of Fund Performance
The performance of Class A shares for the period presented is shown in the Average Annual Total Returns table.
Top Performance Contributors
Allocations
| Positive contributions to the Fund’s performance relative to the benchmark were driven by overweight allocations to A, BBB, BB and not-rated bonds, an underweight to higher quality AAA and AA bonds, an overweight to bonds 17 years to maturity and longer, an underweight to bonds less than 12 years to maturity, and overweights to continuing care retirement community (CCRC) and charter school bonds.
Security selection
| Selection in bonds rated AA, A and BBB, bonds 17 years to maturity and longer, and in special tax, electric, toll road and CCRC bonds added to performance.
Treasury futures
| The use of Treasury fu
tur
es was beneficial to performance during a period when municipal interest rates rose across most of the curve.
Top Performance Detractors
Allocations
| The Fund’s underweight to bonds less than two years to maturity modestly detracted from relative performance.
Security selection
| Selection in housing bonds modestly detracted from performance.
Performance Past Does Not Indicate Future [Text] Past performance does not guarantee future performance.
Line Graph [Table Text Block]
Fund Performance - Growth of 10K
Average Annual Return [Table Text Block]
Average Annual Total Returns (%)1 year5 years10 years
Class A (excluding sales charges) 5.810.802.32
Class A (including sales charges) 2.650.192.00
Bloomberg Municipal Bond Index3.741.182.47
No Deduction of Taxes [Text Block] Performance does not reflect the deduction of taxes that a shareholder may pay on fund distributions or on the redemptions of fund shares.
Updated Performance Information Location [Text Block] Visit
columbiathreadneedleus.com/investment-products/mutual-funds
for more recent performance information.
Net Assets $ 2,038,848,588
Holdings Count | Holding 484
Advisory Fees Paid, Amount $ 9,462,247
Investment Company, Portfolio Turnover 22.00%
Additional Fund Statistics [Text Block]
Key Fund Statistics
Fund net assets
$
2,038,848,588
Total number of portfolio holdings484
Management services fees
(represents 0.46% of Fund average net assets)
$
9,462,247
Portfolio turnover for the reporting period 22%
Holdings [Text Block]
Graphical Representation of Fund
 
Holdings
The tables below show the investment makeup of the Fund represented as a percentage of Fund net assets. Derivatives are excluded from the tables unless otherwise noted. The Fund's portfolio composition is subject to change.
Bond ratings on Fund holdings are divided into categories ranging from highest to lowest credit quality, determined by using the middle rating of Moody’s, S&P and Fitch, after dropping the highest and lowest
availab
le ratings. When ratings are available from only two rating agencies, the lower rating is used. When a rating is available from only one rating agency, that rating is used. If a security is not rated by Moody's, S&P and Fitch, but has a rating by Kroll and/or DBRS, the same methodology is applied to those bonds that would otherwise be not rated. When a bond is not rated by any rating agency, it is designated as “Not rated.” Credit quality rati
ngs a
ssigned by a rating agency are subjective opinions, not statements of fact, and are subject to change, including daily.
Top States/Territories
Texas12.7
%
New York9.4
%
Illinois9.1
%
Pennsylvania7.4
%
Colorado4.5
%
New Jersey4.2
%
California4.2
%
Michigan4.0
%
Florida3.1
%
Puerto Rico2.8
%
Asset Categories
Graphical Representation - Allocation 1 Chart
Credit Quality
Graphical Representation - Allocation 2 Chart
Credit Quality Explanation [Text Block] Bond ratings on Fund holdings are divided into categories ranging from highest to lowest credit quality, determined by using the middle rating of Moody’s, S&P and Fitch, after dropping the highest and lowest
availab
le ratings. When ratings are available from only two rating agencies, the lower rating is used. When a rating is available from only one rating agency, that rating is used. If a security is not rated by Moody's, S&P and Fitch, but has a rating by Kroll and/or DBRS, the same methodology is applied to those bonds that would otherwise be not rated. When a bond is not rated by any rating agency, it is designated as “Not rated.” Credit quality rati
ngs a
ssigned by a rating agency are subjective opinions, not statements of fact, and are subject to change, including daily.
Material Fund Change [Text Block]
On July 26, 2024, the Fund supplemented its Prospectus’ Principal Investment Strategies to reflect that the Fund may enter into tender option bond (TOB) transactions and may invest in derivatives, such as floating rate municipal securities (floaters) and inverse floating rate municipal securities (inverse floaters) to add incremental income, futures (including interest rate and Treasury bond futures) to manage duration and hedge against changes in interest rates, and swaps, including Municipal Market Data Rate Locks (MMD Rate Locks) to manage duration and hedge against changes in interest rates. In addition, the Fund amended its Prospectus’ Principal Risks to include disclosure of the risks associated with investing in these instruments and derivatives generally. These changes became effective on August 1, 2024.
Material Fund Change Strategies [Text Block] On July 26, 2024, the Fund supplemented its Prospectus’ Principal Investment Strategies to reflect that the Fund may enter into tender option bond (TOB) transactions and may invest in derivatives, such as floating rate municipal securities (floaters) and inverse floating rate municipal securities (inverse floaters) to add incremental income, futures (including interest rate and Treasury bond futures) to manage duration and hedge against changes in interest rates, and swaps, including Municipal Market Data Rate Locks (MMD Rate Locks) to manage duration and hedge against changes in interest rates.
Material Fund Change Risks Change [Text Block] In addition, the Fund amended its Prospectus’ Principal Risks to include disclosure of the risks associated with investing in these instruments and derivatives generally.
Summary of Change Legend [Text Block] This is a summary of certain changes to the Fund
dur
ing the reporting period. For more complete information, you may review the Fund’s prospectus, which is available at
columbiathreadneedleus.com/resources/literature
or upon request at 1-800-345-6611.
Updated Prospectus Phone Number 1-800-345-6611
Updated Prospectus Web Address columbiathreadneedleus.com/resources/literature
Columbia Tax-Exempt Fund (Advisor Class)  
Shareholder Report [Line Items]  
Fund Name Columbia Tax-Exempt Fund
Class Name Advisor Class
Trading Symbol CTERX
Annual or Semi-Annual Statement [Text Block] This annual shareholder report contains important information about Columbia Tax-Exempt Fund (the Fund) for the period of August 1, 2023 to July 31, 2024.
Shareholder Report Annual or Semi-Annual annual shareholder report
Additional Information [Text Block] You can find additional information about the Fund at
columbiathreadneedleus.com/resources/literature
. You can also request more information by contacting us at
1-800-345-6611.
Material Fund Change Notice [Text Block] This report describes changes to the Fund that occurred during the reporting period.
Additional Information Phone Number 1-800-345-6611
Additional Information Website columbiathreadneedleus.com/resources/literature
Expenses [Text Block]
What were the Fund costs for the reporting period?
(Based on a hypothetical $10,000 investment)
ClassCost of a $10,000 investmentCost paid as a percentage of a $10,000 investment
Advisor Class
$
57		0.55
%
Expenses Paid, Amount $ 57
Expense Ratio, Percent 0.55%
Factors Affecting Performance [Text Block]
Management's Discussion of Fund Performance
The performance of Advisor Class shares for the period presented is shown in the Average Annual Total Returns table.
Top Performance Contributors
Allocations
| Positive contributions to the Fund’s performance relative to the benchmark were driven by overweight allocations to A, BBB, BB and not-rated bonds, an underweight to higher quality AAA and AA bonds, an overweight to bonds 17 years to maturity and longer, an underweight to bonds less than 12 years to maturity, and overweights to continuing care retirement community (CCRC) and charter school bonds.
Security selection
| Selection in bonds rated AA, A and BBB, bonds 17 years to maturity and longer, and in special tax, electric, toll road and CCRC bonds added to performance.
Treasury futures
| The use of Treasury futures was beneficial to performance during a period when municipal interest rates rose across most of the curve.
Top Performance Detractors
Allocations
| The Fund’s underweight to bonds less than two years to maturity modestly detracted from relative performance.
Security selection
| Selection in housing bonds modestly detracted from performance.
Performance Past Does Not Indicate Future [Text] Past performance does not guarantee future performance.
Line Graph [Table Text Block]
Fund Performance - Growth of 10K
Average Annual Return [Table Text Block]
Average Annual Total Returns (%)1 year5 years10 years
Advisor Class 6.021.002.52
Bloomberg Municipal Bond Index3.741.182.47
No Deduction of Taxes [Text Block] Performance does not reflect the deduction of taxes that a shareholder may pay on fund distributions or on the redemptions of fund shares.
Material Change Date Aug. 01, 2024
Updated Performance Information Location [Text Block] Visit
columbiathreadneedleus.com/investment-products/mutual-funds
for more recent performance information.
Net Assets $ 2,038,848,588
Holdings Count | Holdings 484
Advisory Fees Paid, Amount $ 9,462,247
Investment Company, Portfolio Turnover 22.00%
Additional Fund Statistics [Text Block]
Key Fund Statistics
Fund net assets
$
2,038,848,588
Total number of portfolio holdings484
Managemen
t ser
vices fees
(represents 0.46% of Fund average net assets)
$
9,462,247
Portfolio turnover for the reporting period22%
Holdings [Text Block]
Graphical Representation of Fund
 
Holdings
The tables below show the investment makeup of the Fund represented as a percentage of Fund net assets. Derivatives are excluded from the tables unless otherwise noted. The Fund's portfolio composition is subject to change.
Bond ratings on Fund holdings are divided into categories ranging from highest to lowest credit quality, determined by using the middle rating of Moody’s, S&P and Fitch, after dropping the highest and lowest available ratings. When ratings are available from only two rating agencies, the lower rating is used. When a rating is available from only one rating agency, that rating is used. If a security is not rated by Moody's, S&P and Fitch, but has a rating by Kroll and/or DBRS, the same methodology is applied to those bonds that would otherwise be not rated. When a bond is not rated by any rating agency, it is designated as “Not rated.” Credit quality ratings assigned by a rating agency are subjective opinions, not statements of fact, and are subject to change, including daily.
Top States/Territories
Texas12.7
%
New York9.4
%
Illinois9.1
%
Pennsylvania7.4
%
Colorado4.5
%
New Jersey4.2
%
California4.2
%
Michigan4.0
%
Florida3.1
%
Puerto Rico2.8
%
Asset Categories
Graphical Representation - Allocation 1 Chart
Credit Quality
Graphical Representation - Allocation 2 Chart
Credit Quality Explanation [Text Block] Bond ratings on Fund holdings are divided into categories ranging from highest to lowest credit quality, determined by using the middle rating of Moody’s, S&P and Fitch, after dropping the highest and lowest available ratings. When ratings are available from only two rating agencies, the lower rating is used. When a rating is available from only one rating agency, that rating is used. If a security is not rated by Moody's, S&P and Fitch, but has a rating by Kroll and/or DBRS, the same methodology is applied to those bonds that would otherwise be not rated. When a bond is not rated by any rating agency, it is designated as “Not rated.” Credit quality ratings assigned by a rating agency are subjective opinions, not statements of fact, and are subject to change, including daily.
Material Fund Change [Text Block]
On July 26, 2024, the Fund supplemented its Prospectus’ Principal Investment Strategies to reflect that the Fund may enter into tender option bond (TOB) transactions and may invest in derivatives, such as floating rate municipal securities (floaters) and inverse floating rate municipal securities (inverse floaters) to add incrementa
l inco
me, futures (including interest rate and Treasury bond futures) to manage duration and hedge against changes in interest rates, and swaps, including Municipal Market Data Rate Locks (MMD Rate Locks) to manage duration and hedge against changes in interest rates. In addition, the Fund amended its Prospectus’ Principal Risks to include disclosure of the risks associated with investing in these instruments and derivatives generally. These changes became effective on August 1, 2024.
Material Fund Change Strategies [Text Block] On July 26, 2024, the Fund supplemented its Prospectus’ Principal Investment Strategies to reflect that the Fund may enter into tender option bond (TOB) transactions and may invest in derivatives, such as floating rate municipal securities (floaters) and inverse floating rate municipal securities (inverse floaters) to add incrementa
l inco
me, futures (including interest rate and Treasury bond futures) to manage duration and hedge against changes in interest rates, and swaps, including Municipal Market Data Rate Locks (MMD Rate Locks) to manage duration and hedge against changes in interest rates.
Material Fund Change Risks Change [Text Block] In addition, the Fund amended its Prospectus’ Principal Risks to include disclosure of the risks associated with investing in these instruments and derivatives generally.
Summary of Change Legend [Text Block] This is a summary of certain changes to the Fund during the reporting period. For more complete information, you may review the Fund’s prospectus, which is available at
columbiathreadneedleus.com/resources/literature
or upon request at 1-800-345-6611.
Updated Prospectus Phone Number 1-800-345-6611
Updated Prospectus Web Address columbiathreadneedleus.com/resources/literature
Columbia Tax-Exempt Fund - Class C  
Shareholder Report [Line Items]  
Fund Name Columbia Tax-Exempt Fund
Class Name Class C
Trading Symbol COLCX
Annual or Semi-Annual Statement [Text Block] This annual shareholder report contains important information about Columbia Tax-Exempt Fund (the Fund) for the period of August 1, 2023 to July 31, 2024.
Shareholder Report Annual or Semi-Annual annual shareholder report
Additional Information [Text Block] You can find additional information about the Fund at
columbiathreadneedleus.com/resources/literature
. You can also request more information by contacting us at
1-800-345-6611.
Material Fund Change Notice [Text Block] This report describes changes to the Fund that occurred during the reporting period.
Additional Information Phone Number 1-800-345-6611
Additional Information Website columbiathreadneedleus.com/resources/literature
Expenses [Text Block]
What were the Fund costs for the reporting period?
(Based on a hypothetical $10,000 investment)
ClassCost of a $10,000 investmentCost paid as a percentage of a $10,000 investment
Class C
$
138		1.35
%
Expenses Paid, Amount $ 138
Expense Ratio, Percent 1.35%
Factors Affecting Performance [Text Block]
Management's Discussion of Fund Performance
The performance of Class C shares for the period presented is shown in the Average Annual Total Returns table.
Top Performance Contributors
Allocations
| Positive contributions to the Fund’s performance relative to the benchmark were driven by overweight allocations to A, BBB, BB and not-rated bonds, an underweight to higher quality AAA and AA bonds, an overweight to bonds 17 years to maturity and longer, an underweight to bonds less than 12 years to maturity, and overweights to continuing care retirement community (CCRC) and charter school bonds.
Security selection
| Selection in bonds rated AA, A and BBB, bonds 17 years to maturity and longer, and in special tax, electric, toll road and CCRC bonds added to performance.
Treasury futures
| The use of Treasury futures was beneficial to performance during a period when municipal interest rates rose across most of the curve.
Top Performance Detractors
Allocations
| The Fund’s underweight to bonds less than two years to maturity modestly detracted from relative performance.
Security selection
| Selection in housing bonds modestly detracted from performance.
Performance Past Does Not Indicate Future [Text] Past performance does not guarantee future performance.
Line Graph [Table Text Block]
Fund Performance - Growth of 10K
Average Annual Return [Table Text Block]
Average Annual Total Returns (%)1 year5 years10 years
Class C (excluding sales charges) 5.170.181.68
Class C (including sales charges) 4.170.181.68
Bloomberg Municipal Bond Index3.741.182.47
No Deduction of Taxes [Text Block] Performance does not reflect the deduction of taxes that a shareholder may pay on fund distributions or on the redemptions of fund shares.
Material Change Date Aug. 01, 2024
Updated Performance Information Location [Text Block] Visit
columbiathreadneedleus.com/investment-products/mutual-funds
for more recent performance information.
Net Assets $ 2,038,848,588
Holdings Count | Holdings 484
Advisory Fees Paid, Amount $ 9,462,247
Investment Company, Portfolio Turnover 22.00%
Additional Fund Statistics [Text Block]
Key Fund Statistics
Fund net assets
$
2,038,848,588
Total number of portfolio holdings484
Management services fees
(represents 0.46% of Fund average net assets)
$
9,462,247
Portfolio turnover for the reporting period 22%
Holdings [Text Block]
Graphical
Representation
of Fund
 
Holdings
The tables below show the investment makeup of the Fund represented as a percentage of Fund net assets. Derivatives are excluded from the tables unless otherwise noted. The Fund's portfolio composition is subject to change.
Bond ratings on Fund holdings are divided into categories ranging from highest to lowest credit quality, determined by using the middle rating of Moody’s, S&P and Fitch, after dropping the highest and lowest available ratings. When ratings are available from only two rating agencies, the lower rating is used. When a rating is available from only one rating agency, that rating is used. If a security is not rated by Moody's, S&P and Fitch, but has a rating by Kroll and/or DBRS, the same methodology is applied to those bonds that would otherwise be not rated. When a bond is not rated by any rating agency, it is designated as “Not rated.” Credit quality ratings
assigned
by a rating agency are subjective opinions, not statements of fact, and are subject to
change
, including daily.
Top States/Territories
Texas12.7
%
New York9.4
%
Illinois9.1
%
Pennsylvania7.4
%
Colorado4.5
%
New Jersey4.2
%
California4.2
%
Michigan4.0
%
Florida3.1
%
Puerto Rico2.8
%
Asset Categories
Graphical Representation - Allocation 1 Chart
Credit Quality
Graphical Representation - Allocation 2 Chart
Credit Quality Explanation [Text Block] Bond ratings on Fund holdings are divided into categories ranging from highest to lowest credit quality, determined by using the middle rating of Moody’s, S&P and Fitch, after dropping the highest and lowest available ratings. When ratings are available from only two rating agencies, the lower rating is used. When a rating is available from only one rating agency, that rating is used. If a security is not rated by Moody's, S&P and Fitch, but has a rating by Kroll and/or DBRS, the same methodology is applied to those bonds that would otherwise be not rated. When a bond is not rated by any rating agency, it is designated as “Not rated.” Credit quality ratings
assigned
by a rating agency are subjective opinions, not statements of fact, and are subject to
change
, including daily.
Material Fund Change [Text Block]
Certain Fund Changes
This is a summary of certain changes to the Fund during the reporting period. For more complete information, you may review the Fund’s prospectus, which is available at
columbiathreadneedleus.com/resources/literature
or upon request at 1-800-345-6611.
On July 26, 2024, the Fund supplemented its Prospectus’ Principal Investment Strategies to reflect that the Fund may enter into tender option bond (TOB) transactions and may invest in derivatives, such as floating rate municipal securities (floaters) and inverse floating rate municipal securities (inverse floaters) to add incremental income, futures (including interest rate and Treasury bond futures) to manage duration and hedge against changes in interest rates, and swaps, including Municipal Market Data Rate Locks (MMD Rate Locks) to manage duration and hedge against changes in interest rates. In addition, the Fund amended its Prospectus’ Principal Risks to include disclosure of the risks associated with investing in these instruments and derivatives generally. These changes became effective on August 1, 2024.
Material Fund Change Strategies [Text Block] On July 26, 2024, the Fund supplemented its Prospectus’ Principal Investment Strategies to reflect that the Fund may enter into tender option bond (TOB) transactions and may invest in derivatives, such as floating rate municipal securities (floaters) and inverse floating rate municipal securities (inverse floaters) to add incremental income, futures (including interest rate and Treasury bond futures) to manage duration and hedge against changes in interest rates, and swaps, including Municipal Market Data Rate Locks (MMD Rate Locks) to manage duration and hedge against changes in interest rates.
Material Fund Change Risks Change [Text Block] In addition, the Fund amended its Prospectus’ Principal Risks to include disclosure of the risks associated with investing in these instruments and derivatives generally.
Summary of Change Legend [Text Block] This is a summary of certain changes to the Fund during the reporting period. For more complete information, you may review the Fund’s prospectus, which is available at
columbiathreadneedleus.com/resources/literature
or upon request at 1-800-345-6611.
Updated Prospectus Phone Number 1-800-345-6611
Updated Prospectus Web Address columbiathreadneedleus.com/resources/literature
Columbia Tax-Exempt Fund - Institutional Class  
Shareholder Report [Line Items]  
Fund Name Columbia Tax-Exempt Fund
Class Name Institutional Class
Trading Symbol CTEZX
Annual or Semi-Annual Statement [Text Block] This annual shareholder report contains important information about Columbia Tax-Exempt Fund (the Fund) for the period of August 1, 2023 to July 31, 2024.
Shareholder Report Annual or Semi-Annual annual shareholder report
Additional Information [Text Block] You can find additional information about the Fund at
columbiathreadneedleus.com/resources/literature
. You can also request more information by contacting us at
1-800-345-6611.
Material Fund Change Notice [Text Block] This report describes changes to the Fund that occurred during the reporting period.
Additional Information Phone Number 1-800-345-6611
Additional Information Website columbiathreadneedleus.com/resources/literature
Expenses [Text Block]
What were the Fund costs for the reporting period?
(Based on a hypothetical $10,000 investment)
ClassCost of a $10,000 investmentCost paid as a percentage of a $10,000 investment
Institutional Class
$
57		0.55
%
Expenses Paid, Amount $ 57
Expense Ratio, Percent 0.55%
Factors Affecting Performance [Text Block]
Management's Discussion of Fund Performance
The performance of Institutional Class shares for the period presented is shown in the Average Annual Total Returns table.
Top Performance Contributors
Allocations
| Positive contributions to the Fund’s performance relative to the benchmark were driven by overweight allocations to A, BBB, BB and not-rated bonds, an underweight to higher quality AAA and AA bonds, an overweight to bonds 17 years to maturity and longer, an underweight to bonds less than 12 years to maturity, and overweights to continuing care retirement community (CCRC) and charter school bonds.
Security selection
| Selection in bonds rated AA, A and BBB, bonds 17 years to maturity and longer, and in special tax, electric, toll road and CCRC bonds added to performance.
Treasury futures
| The use of Treasury futures was beneficial to performance during a period when municipal interest rates rose across most of the curve.
Top Performance Detractors
Allocations
| The Fund’s underweight to bonds less than two years to maturity modestly detracted from relative performance.
Security selection
| Selection in housing bonds modestly detracted from performance.
Performance Past Does Not Indicate Future [Text] Past performance does not guarantee future performance.
Line Graph [Table Text Block]
Fund Performance - Growth of 10K
Average Annual Return [Table Text Block]
Average Annual Total Returns (%)1 year5 years10 years
Institutional Class5.930.982.52
Bloomberg Municipal Bond Index3.741.182.47
No Deduction of Taxes [Text Block] Performance does not reflect the deduction of taxes that a shareholder may pay on fund distributions or on the redemptions of fund shares.
Material Change Date Aug. 01, 2024
Updated Performance Information Location [Text Block] Visit
columbiathreadneedleus.com/investment-products/mutual-funds
for more recent performance information.
Net Assets $ 2,038,848,588
Holdings Count | Holdings 484
Advisory Fees Paid, Amount $ 9,462,247
Investment Company, Portfolio Turnover 22.00%
Additional Fund Statistics [Text Block] Key Fund Statistics
Fund net assets
$
2,038,848,588
Total number of portfolio holdings484
Management services fees
(represents 0.46% of Fund average net assets)
$
9,462,247
Portfolio turnover for the reporting period 22%
Holdings [Text Block]
Graphical Representation of Fund
 
Holdings
The tables below show the investment makeup of the Fund represented as a percentage of Fund net assets. Derivatives are excluded from the tables unless otherwise noted. The Fund's portfolio composition is subject to change.
Bond ratings on Fund holdings are divided into categories ranging from highest to lowest credit quality, determined by using the middle rating of Moody’s, S&P and Fitch, after dropping the highest and lowest available ratings. When ratings are available from only two rating agencies, the lower rating is used. When a rating is available from only one rating agency, that rating is used. If a security is not rated by Moody's, S&P and Fitch, but has a rating by Kroll and/or DBRS, the same methodology is applied to those bonds that would otherwise be not rated. When a bond is not rated by any rating agency, it is designated as “Not rated.” Credit quality ratings assigned by a
rating
agency are subjective opinions, not statements of fact, and are subject to change, including daily.
Top States/Territories
Texas12.7
%
New York9.4
%
Illinois9.1
%
Pennsylvania7.4
%
Colorado4.5
%
New Jersey4.2
%
California4.2
%
Michigan4.0
%
Florida3.1
%
Puerto Rico2.8
%
Asset Categories
Graphical Representation - Allocation 1 Chart
Credit Quality
Graphical Representation - Allocation 2 Chart
Credit Quality Explanation [Text Block] Bond ratings on Fund holdings are divided into categories ranging from highest to lowest credit quality, determined by using the middle rating of Moody’s, S&P and Fitch, after dropping the highest and lowest available ratings. When ratings are available from only two rating agencies, the lower rating is used. When a rating is available from only one rating agency, that rating is used. If a security is not rated by Moody's, S&P and Fitch, but has a rating by Kroll and/or DBRS, the same methodology is applied to those bonds that would otherwise be not rated. When a bond is not rated by any rating agency, it is designated as “Not rated.” Credit quality ratings assigned by a
rating
agency are subjective opinions, not statements of fact, and are subject to change, including daily.
Material Fund Change [Text Block]
Certain Fund Changes
This is a summary of certain changes to the Fund during the reporting period. For more complete information, you may review the Fund’s prospectus, which is available at
columbiathreadneedleus.com/resources/literature
or upon request at 1-800-345-6611.
On July 26, 2024, the Fund supplemented its Prospectus’ Principal Investment Strategies to
reflect
that the Fund may enter into tender option bond (TOB) transactions and may invest in derivatives, such as floating rate municipal securities (floaters) and inverse floating rate municipal securities (inverse floaters) to add incremental income, futures (including interest rate and Treasury bond futures) to manage duration and hedge against changes in interest rates, and swaps, including Municipal Market Data Rate Locks (MMD Rate Locks) to manage duration and hedge against changes in interest rates. In addition, the Fund amended its Prospectus’ Principal Risks to include disclosure of the risks associated with investing in these instruments and derivatives generally. These changes became effective on August 1, 2024.
Material Fund Change Strategies [Text Block] On July 26, 2024, the Fund supplemented its Prospectus’ Principal Investment Strategies to
reflect
that the Fund may enter into tender option bond (TOB) transactions and may invest in derivatives, such as floating rate municipal securities (floaters) and inverse floating rate municipal securities (inverse floaters) to add incremental income, futures (including interest rate and Treasury bond futures) to manage duration and hedge against changes in interest rates, and swaps, including Municipal Market Data Rate Locks (MMD Rate Locks) to manage duration and hedge against changes in interest rates.
Material Fund Change Risks Change [Text Block] In addition, the Fund amended its Prospectus’ Principal Risks to include disclosure of the risks associated with investing in these instruments and derivatives generally.
Summary of Change Legend [Text Block] This is a summary of certain changes to the Fund during the reporting period. For more complete information, you may review the Fund’s prospectus, which is available at
columbiathreadneedleus.com/resources/literature
or upon request at 1-800-345-6611.
Updated Prospectus Phone Number 1-800-345-6611
Updated Prospectus Web Address columbiathreadneedleus.com/resources/literature
Columbia Tax-Exempt Fund - Institutional 2 Class  
Shareholder Report [Line Items]  
Fund Name Columbia Tax-Exempt Fund
Class Name Institutional 2 Class
Trading Symbol CADMX
Annual or Semi-Annual Statement [Text Block] This annual shareholder report contains important information about Columbia Tax-Exempt Fund (the Fund) for the period of August 1, 2023 to July 31, 2024.
Shareholder Report Annual or Semi-Annual annual shareholder report
Additional Information [Text Block] You can find additional information about the Fund at
columbiathreadneedleus.com/resources/literature
. You can also request more information by contacting us at
1-800-345-6611.
Material Fund Change Notice [Text Block] This report describes changes to the Fund that occurred during the reporting period.
Additional Information Phone Number 1-800-345-6611
Additional Information Website columbiathreadneedleus.com/resources/literature
Expenses [Text Block]
What were the Fund costs for the reporting period?
(Based on a hypothetical $10,000 investment)
ClassCost of a $10,000 investmentCost paid as a percentage of a $10,000 investment
Institutional 2 Class
$
55		0.53
%
Expenses Paid, Amount $ 55
Expense Ratio, Percent 0.53%
Factors Affecting Performance [Text Block]
Management's Discussion of Fund Performance
The performance of Institutional 2 Class shares for the period presented is shown in the Average Annual Total Returns table.
Top Performance Contributors
Allocations
| Positive contributions to the Fund’s performance relative to the benchmark were driven by overweight allocations to A, BBB, BB and not-rated bonds, an underweight to higher quality AAA and AA bonds, an overweight to bonds 17 years to maturity and longer, an underweight to bonds less than 12 years to maturity, and overweights to continuing care retirement community (CCRC) and charter school bonds.
Security selection
| Selection in bonds rated AA, A and BBB, bonds 17
years
to maturity and longer, and in special tax, electric, toll road and CCRC bonds added to performance.
Treasury futures
| The use of Treasury futures was beneficial to performance during a period when municipal interest rates rose across most of the curve.
Top Performance Detractors
Allocations
| The Fund’s underweight to bonds less than two years to maturity modestly detracted from relative performance.
Security selection
| Selection in housing bonds modestly detracted from performance.
Performance Past Does Not Indicate Future [Text] Past performance does not guarantee future performance.
Line Graph [Table Text Block]
Fund Performance - Growth of 10K
Average Annual Return [Table Text Block]
Average Annual Total Returns (%)1 year5 years10 years
Institutional 2 Class6.031.012.55
Bloomberg Municipal Bond Index3.741.182.47
No Deduction of Taxes [Text Block] Performance does not reflect the deduction of taxes that a shareholder may pay on fund distributions or on the redemptions of fund shares.
Material Change Date Aug. 01, 2024
Updated Performance Information Location [Text Block] Visit
columbiathreadneedleus.com/investment-products/mutual-funds
for more recent performance information.
Net Assets $ 2,038,848,588
Holdings Count | Holdings 484
Advisory Fees Paid, Amount $ 9,462,247
Investment Company, Portfolio Turnover 22.00%
Additional Fund Statistics [Text Block]
Key Fund Statistics
Fund net assets
$
2,038,848,588
Total number of portfolio holdings484
Management services fees
(represents 0.46% of Fund average net assets)
$
9,462,247
Portfolio turnover for the reporting period 22%
Holdings [Text Block]
Graphical Representation of Fund
 
Holdings
The tables below show the investment makeup of the Fund represented as a percentage of Fund net assets. Derivatives are excluded from the tables unless otherwise noted. The Fund's portfolio composition is subject to change.
Bond ratings on Fund holdings are divided into categories ranging from highest to lowest credit quality, determined by using the middle rating of Moody’s, S&P and Fitch, after dropping the highest and lowest available ratings. When ratings are available from only two rating agencies, the lower rating is used. When a rating is available from only one rating agency, that rating is used. If a security is not rated by Moody's, S&P and Fitch, but has a rating by Kroll and/or DBRS, the same methodology is applied to those bonds that would otherwise be not rated. When a bond is not rated by any rating agency, it is designated as “Not rated.” Credit quality ratings assigned by a rating agency are subjective opinions, not statements of fact, and are subject to change, including daily.
Top States/Territories
Texas12.7
%
New York9.4
%
Illinois9.1
%
Pennsylvania7.4
%
Colorado4.5
%
New Jersey4.2
%
California4.2
%
Michigan4.0
%
Florida3.1
%
Puerto Rico2.8
%
Asset Categories
Graphical Representation - Allocation 1 Chart
Credit Quality
Graphical Representation - Allocation 2 Chart
Credit Quality Explanation [Text Block] Bond ratings on Fund holdings are divided into categories ranging from highest to lowest credit quality, determined by using the middle rating of Moody’s, S&P and Fitch, after dropping the highest and lowest available ratings. When ratings are available from only two rating agencies, the lower rating is used. When a rating is available from only one rating agency, that rating is used. If a security is not rated by Moody's, S&P and Fitch, but has a rating by Kroll and/or DBRS, the same methodology is applied to those bonds that would otherwise be not rated. When a bond is not rated by any rating agency, it is designated as “Not rated.” Credit quality ratings assigned by a rating agency are subjective opinions, not statements of fact, and are subject to change, including daily.
Material Fund Change [Text Block]
Certain Fund Changes
This is a summary of certain changes to the Fund during the reporting period. For more complete information, you may review the Fund’s prospectus, which is available at
columbiathreadneedleus.com/resources/literature
or upon request at 1-800-345-6611.
On July 26, 2024, the Fund supplemented its Prospectus’ Principal
Investment
Strategies to reflect that the Fund may enter into tender option bond (TOB) transactions and may invest in derivatives, such as floating rate municipal securities (floaters) and inverse floating rate municipal securities (inverse floaters) to add incremental income, futures (including interest rate and Treasury bond futures) to manage duration and hedge against changes in interest rates, and swaps, including Municipal Market Data Rate Locks (MMD Rate Locks) to manage duration and hedge against changes in interest rates. In addition, the Fund amended its Prospectus’ Principal Risks to include disclosure of the risks associated with investing in these instruments and derivatives generally. These changes became effective on August 1, 2024.
Material Fund Change Strategies [Text Block] On July 26, 2024, the Fund supplemented its Prospectus’ Principal
Investment
Strategies to reflect that the Fund may enter into tender option bond (TOB) transactions and may invest in derivatives, such as floating rate municipal securities (floaters) and inverse floating rate municipal securities (inverse floaters) to add incremental income, futures (including interest rate and Treasury bond futures) to manage duration and hedge against changes in interest rates, and swaps, including Municipal Market Data Rate Locks (MMD Rate Locks) to manage duration and hedge against changes in interest rates.
Material Fund Change Risks Change [Text Block] In addition, the Fund amended its Prospectus’ Principal Risks to include disclosure of the risks associated with investing in these instruments and derivatives generally.
Summary of Change Legend [Text Block] This is a summary of certain changes to the Fund during the reporting period. For more complete information, you may review the Fund’s prospectus, which is available at
columbiathreadneedleus.com/resources/literature
or upon request at 1-800-345-6611.
Updated Prospectus Phone Number 1-800-345-6611
Updated Prospectus Web Address columbiathreadneedleus.com/resources/literature
Columbia Tax-Exempt Fund - Institutional 3 Class  
Shareholder Report [Line Items]  
Fund Name Columbia Tax-Exempt Fund
Class Name Institutional 3 Class
Trading Symbol CTEYX
Annual or Semi-Annual Statement [Text Block] This annual shareholder report contains important information about Columbia Tax-Exempt Fund (the Fund) for the period of August 1, 2023 to July 31, 2024.
Shareholder Report Annual or Semi-Annual annual shareholder report
Additional Information [Text Block] You can find additional information about the Fund at
columbiathreadneedleus.com/resources/literature
. You can also request more information by contacting us at
1-800-345-6611.
Material Fund Change Notice [Text Block] This report describes changes to the Fund that occurred during the reporting period.
Additional Information Phone Number 1-800-345-6611
Additional Information Website columbiathreadneedleus.com/resources/literature
Expenses [Text Block]
What were the Fund costs for the reporting period?
(Based on a hypothetical $10,000 investment)
ClassCost of a $10,000 investmentCost paid as a percentage of a $10,000 investment
Institutional 3 Class
$
50		0.49
%
Expenses Paid, Amount $ 50
Expense Ratio, Percent 0.49%
Factors Affecting Performance [Text Block]
Management's Discussion of Fund Performance
The performance of Institutional 3 Class shares for the period presented is shown in the Average Annual Total Returns table.
Top Performance Contributors
Allocations
| Positive contributions to the Fund’s performance relative to the benchmark were driven by overweight allocations to A, BBB, BB and not-rated bonds, an underweight to higher quality AAA and AA bonds, an overweight to bonds 17 years to maturity and longer, an underweight to bonds less than 12 years to maturity, and overweights to continuing care retirement community (CCRC) and charter school bonds.
Security selection
| Selection in bonds rated AA, A and BBB, bonds 17 years to maturity and longer, and in special tax, electric, toll road and CCRC bonds added to performance.
Treasury futures
| The use of Treasury futures was beneficial to
performance
during a period when municipal interest rates rose across most of the curve.
Top Performance Detractors
Allocations
| The Fund’s underweight to bonds less than two years to maturity modestly detracted from relative performance.
Security selection
| Selection in housing bonds modestly detracted from performance.
Performance Past Does Not Indicate Future [Text] Past performance does not guarantee future performance.
Line Graph [Table Text Block]
Fund Performance - Growth of 10K
Average Annual Return [Table Text Block]
Average Annual Total Returns (%)1 year5 years10 years
Institutional 3 Class
(a)
6.081.072.51
Bloomberg Municipal Bond Index3.741.182.47
(a)
The returns shown for periods prior to March 1, 2017 (including returns for the Life of the Fund, if shown, which are since Fund inception) include the returns of Class A. These returns are adjusted to reflect any higher class-related operating expenses of the newer share classes, as applicable. Please visit
columbiathreadneedleus.com/investor/investment-products/mutual-funds/appended-performance
for more information.
No Deduction of Taxes [Text Block] Performance does not reflect the deduction of taxes that a shareholder may pay on fund distributions or on the redemptions of fund shares.
Material Change Date Aug. 01, 2024
Updated Performance Information Location [Text Block] Visit
columbiathreadneedleus.com/investment-products/mutual-funds
for more recent performance information.
Net Assets $ 2,038,848,588
Holdings Count | Holdings 484
Advisory Fees Paid, Amount $ 9,462,247
Investment Company, Portfolio Turnover 22.00%
Additional Fund Statistics [Text Block]
Key Fund Statistics
Fund net assets
$
2,038,848,588
Total number of portfolio holdings484
Management services fees
(represents 0.46% of Fund average net assets)
$
9,462,247
Portfolio turnover for the reporting period 22%
Holdings [Text Block]
Graphical Representation of Fund
 
Holdings
The tables below show the investment makeup of the Fund represented as a percentage of Fund net assets. Derivatives are excluded from the tables unless otherwise noted. The Fund's portfolio composition is subject to change.
Bond ratings on Fund holdings are divided into categories ranging from highest to lowest credit quality, determined by using the middle rating of Moody’s, S&P and Fitch, after dropping the highest and lowest available ratings. When ratings are available from only two rating agencies, the lower rating is used. When a rating is available from only one rating agency, that rating is used. If a security is not rated by Moody's, S&P and Fitch, but has a rating by Kroll and/or DBRS, the same methodology is applied to those bonds that would otherwise be not rated. When a bond is not rated by any rating agency, it is designated as “Not rated.” Credit quality ratings assigned by a rating agency are subjective opinions, not statements of fact, and are subject to change,
including
daily.
Top States/Territories
Texas12.7
%
New York9.4
%
Illinois9.1
%
Pennsylvania7.4
%
Colorado4.5
%
New Jersey4.2
%
California4.2
%
Michigan4.0
%
Florida3.1
%
Puerto Rico2.8
%
Asset Categories
Graphical Representation - Allocation 1 Chart
Credit Quality
Graphical Representation - Allocation 2 Chart
Credit Quality Explanation [Text Block] Bond ratings on Fund holdings are divided into categories ranging from highest to lowest credit quality, determined by using the middle rating of Moody’s, S&P and Fitch, after dropping the highest and lowest available ratings. When ratings are available from only two rating agencies, the lower rating is used. When a rating is available from only one rating agency, that rating is used. If a security is not rated by Moody's, S&P and Fitch, but has a rating by Kroll and/or DBRS, the same methodology is applied to those bonds that would otherwise be not rated. When a bond is not rated by any rating agency, it is designated as “Not rated.” Credit quality ratings assigned by a rating agency are subjective opinions, not statements of fact, and are subject to change,
including
daily.
Material Fund Change [Text Block]
Certain Fund
Changes
This is a summary of certain changes to the Fund during the reporting period. For more complete information, you may review the Fund’s prospectus, which is available at
columbiathreadneedleus.com/resources/literature
or upon request at 1-800-345-6611.
On July 26, 2024, the Fund supplemented its Prospectus’ Principal Investment Strategies to reflect that the Fund may enter into tender option bond (TOB) transactions and may invest in derivatives, such as floating rate municipal securities (floaters) and inverse floating rate municipal securities (inverse floaters) to add incremental income, futures (including interest rate and Treasury bond futures) to manage duration and hedge against changes in interest rates, and swaps, including Municipal Market Data Rate Locks (MMD Rate Locks) to manage duration and hedge against changes in interest rates. In addition, the Fund amended its Prospectus’ Principal Risks to include disclosure of the risks associated with investing in these instruments and derivatives generally. These changes became effective on August 1, 2024.
Material Fund Change Strategies [Text Block] On July 26, 2024, the Fund supplemented its Prospectus’ Principal Investment Strategies to reflect that the Fund may enter into tender option bond (TOB) transactions and may invest in derivatives, such as floating rate municipal securities (floaters) and inverse floating rate municipal securities (inverse floaters) to add incremental income, futures (including interest rate and Treasury bond futures) to manage duration and hedge against changes in interest rates, and swaps, including Municipal Market Data Rate Locks (MMD Rate Locks) to manage duration and hedge against changes in interest rates.
Material Fund Change Risks Change [Text Block] In addition, the Fund amended its Prospectus’ Principal Risks to include disclosure of the risks associated with investing in these instruments and derivatives generally.
Summary of Change Legend [Text Block] This is a summary of certain changes to the Fund during the reporting period. For more complete information, you may review the Fund’s prospectus, which is available at
columbiathreadneedleus.com/resources/literature
or upon request at 1-800-345-6611.
Updated Prospectus Phone Number 1-800-345-6611
Updated Prospectus Web Address columbiathreadneedleus.com/resources/literature